Exoplanet Kepler-159d discovered

Simulated view of the Kepler-159 system. Kepler-159b and c are planets that were detected by the Kepler spacecraft. Kepler-159d was discovered at Western University on the basis of its gravitational effects on 159b and 159c. Click above for a larger HD version.

The as-yet unnamed planet with the provisional designation
Kepler-159d has a mass comparable to that of Saturn, the
second-largest planet in our solar system, and like Saturn is likely
mostly composed of gases with no distinct solid surface. Whether 159d
has rings or moons like Saturn does is unknown. 159d *is* known to
orbit within its
star's Habitable
Zone where temperatures are in the range suitable for Earth-life
but there is no information on whether there is actually any life in the system.

The central star of this planetary system is about 380 parsecs (1200 light-years) away , and is a red dwarf star
(spectral class M0V) with a mass estimated at 52% of that of our
Sun. Its surface temperature is about 3600 Celsius (3893 Kelvin)
while the Sun's is 5500C (5770 K) (Muirhead et al. 2012; Mathur et
al. 2017)

Kepler-159b and 159c are two planets already known in the system,
detected from their passages in front of the Kepler-159 star by
the Kepler
planet-hunting spacecraft. Kepler-159d was not seen by the Kepler
planet-hunters, rather it was variations in the orbits of Kepler-159b and c
that allowed researchers at Western University in London Canada to deduce the presence of planet 159d.

Chris Fox, lead author on the paper, first reported the new planet at a recent
scientific conference in Cambridge England. Said Fox, "Ever since I was a kid, I've wanted to visit alien planets. Finding new worlds is the next best thing."